Driving on ice: The Vauxhall Ampera takes on the frozen Baltic Sea

During the chilly winter months, the roads out of Estonia's capital Tallinn are a frozen wasteland. An almost endless stretch of snow-covered tarmac, lined by icy forests of birch with little more than the odd decrepit building and tiny village breaking up the otherwise barren landscape.

Suddenly, the sat-nav in the Vauxhall Ampera I'm currently piloting flashes up something interesting. The roads we are driving on appear to lead straight into the sea but peering through the salt-splattered windscreen says otherwise.